Lopping shears having a pair of elongated members disposed for cooperative engagement about a pivotable joint are widely used. Each of such members generally comprises a jaw, typically made of stamped or forged metal or other suitable material, having an opposed force-applying end or tang connected to a long handle. Such configuration gives the user extra leverage to perform the desired cutting operation, and extended reach to trim distance tree branches and the like. In anvil-type loppers, one of the jaws is formed as a blade while the other jaw is configured as an anvil.
Lopper handles must be sufficiently strong to withstand the forces involved in cutting heavy growth. Although such handles have often been made of wood, to reduce forearm fatigue, more recent prior art loppers have included hollow handles made of fiberglass or other suitable material. In both of these cases, however, lopper handles are attached to the tang of the jaws in a fairly similar manner. Specifically and as shown in U.S. Pat. No. 5,020,222 issued Jun. 4, 1991 to Gosselin et al., after the tang has been inserted into the handle, a fastener such as a rivet or the like is driven into the handle through an end cap and the annealed portion of the tang. In the case of hollow handles, a tubular insert is disposed interiorly of the handle at the end disposed to receive the tang. To increase comfort, a handle grip conforming to the hands of the user and preferably made of moldable material is formed as a separate operation and then fitted onto the end of the handles.
Other examples of prior art loppers are described in U.S. Pat. No. 3,372,478 issued Mar. 12, 1968 to Wallace et al., and in U.S. Pat. No. 4,964,216 issued Oct. 23, 1990 to Gosselin. In all of these instances, assembling the handles as described above is typically preceded by assembling the jaws and pivot.
Shearing heavy growth such as tree limbs on the order of two inches in diameter requires considerable force. To provide additional leverage, lopping shears are often provided with extra long handles. However, such loppers tend to be overly heavy, awkward to manipulate, and costly. These constraints have already been recognized and addressed by those skilled in the art. U.S. Pat. No. 5,020,222 to Gosselin discloses a compound action lopper in which an additional lever member connected to one of the jaws increases the cutting force transmitted to the jaws, thereby facilitating the cutting operation. Such structure provides the additional leverage desired, without unduly augmenting the length of the handles. Other ways to transmit a significant amount of force to the jaws of a pivoted tool, although to the inventor's knowledge not conventionally used with loppers, are well known. Examples of such other tools capable of applying a significant cutting force to the jaws are described in U.S. Pat. No. 1,689,648 issued Oct. 30, 1928 to Voleske and U.S. Pat. No. 1,915,404 issued Jun. 27, 1933 to Clifton. In both of these cases, the pivoting movement of a handle is transmitted to the jaws of the shears by a pair of intermeshing gear segments.
While loppers of the type described in the foregoing suitably perform the desired cutting function, it can be readily appreciated that these prior art structures have several shortcomings. First, prior art loppers configured for increased leverage typically include various components which require in some cases several manufacturing steps, followed by the assembly of these components, thereby potentially increasing the weight of these devices and their cost. In addition, in normal use loppers are typically guided by the user through areas heavily congested by branches of trees or plants to reach a limb to be trimmed. Accordingly, these many components increase the tendency of the loppers to become caught in these branches.
In light of the foregoing, it appears desirable to provide a lopper which can alleviate the problems associated with conventional items of that kind, i.e., which includes fewer components to reduce its cost and weight and facilitate its assembly, which is compact in configuration while providing increased leverage, and which is less susceptible to being caught in congested foliage areas.
It can also be recognized that prior art methods used to manufacture loppers have certain obvious disadvantages. These methods typically require manufacturing various components such as jaws, levers, handles, grips, end caps, or inserts, and subsequently assembling these components preferably into subassemblies, thereby increasing material handling requirements which generally translates into higher unit cost.
Thus, the foregoing indicates that, not only is it desirable to provide loppers with fewer components less prone to being caught in heavy foliage areas, it is also desirable to provide loppers which are engineered to lend themselves to functional assembly during, as opposed to subsequent to, the manufacturing process, or which otherwise reduce the number of operations required to manufacture these tools, while having all necessary features typically desired by users of these tools.